高铬铸钢和高速钢轧辊的氧化行为

Oxidation behavior of high-Cr cast steel and high speed steel rolls

采用增重法对比研究了温度及环境对高铬铸钢和高速钢轧辊氧化行为的影响,并采用超高温激光共聚焦显微镜观察了材料氧化膜的形成特征。结果表明:高速钢组织为分布在基体上V的颗粒或杆状MC型碳化物及晶界Cr、Mo共晶碳化物,而高铬铸钢组织为网状共晶M7C碳化物。在高温氧化过程中,高速钢基体中的MC型碳化物周围快速生成氧化膜并长大,抑制了均匀氧化膜的形成,导致高速钢轧辊氧化膜的不均匀性和生长速率均高于高铬铸钢轧辊。

Effects of temperature and atmosphere on oxidation behavior of high-Cr cast steel and high speed steel rolls were studied by means of mass gain method,and the formation characteristics of the oxidation film were in situ observed on an ultra-high temperature laser confocal microscopy.The results show that the microstructure of the high speed steel consists of granular or rod-like MC carbides of V distributed in matrix and eutectic carbides of Cr and Mo distributed in gain boundaries;while the microstructure of the high-Cr cast steel consists of network eutectic M7C3 carbides.During high temperature oxidization processes,the oxidization films quickly form and grow around the MC carbides in matrix,which restrains the formation of uniform oxidization film,and leads to that the oxidation film on the high speed steel roll has higher inhomogeneity and growth rate than that of the high-Cr cast steel roll.